The Emotional Brain - Joseph LeDoux

zondag 17 april 2011 21:34

I read this book, because I was looking at Minsky's "The Emotion Machine" on Amazon and some reviewer wrote that it was odd that Minsky didn't quote LeDoux because his book was supposedly the "de facto standard".

I don't think the reviewer was right. This book can never be a standard, because it only features a single emotion in depth - fear.

But that doesn't mean the book isn't interesting. I have learned some very interesting things from it:

LeDoux claims that cognitive science has deliberately excluded emotion from its field of research. Now I studied Cognitive Science and I have never heard this claim before. But I have to admit 'emotion' was not a subject I came across in my study. So this is interesting. The omission may have been deliberate.

The book contains an brilliant account of the history of the search for emotion.

LeDoux explains the role of the Amygdala in the functioning of the brain better then I have seen before.

The dual processing of emotion via an unconscious route (via the Amygdala) and a conscious route (via the Prefrontal Cortex) is fascinating and truly insightful.

LeDoux should have left it at that. A fine account of the way fear works in the human brain and the rest of the body.

But he didn't.

The book is written as if the editor came to him when he was done and said "but what about feelings?". So he emphasises the importance of the strong and violent nature of the feelings that can accompany fear and other emotions and he admits that science as yet has no answer to the question how it is that these brain states are actually felt by humans and other animals (the mind-body problem).

Being that as it may, LeDoux then goes on to offer his own answer to that problem. He starts out by describing working memory as the basis of consciousness. Which is fine. But not enough, as he himself claims: "I admit that I've passed the emotional consciousness buck" (p. 282) So he continues with three ingredients needed for feelings:

Direct Amygdala Influences on the Cortex

Amygdala-Triggered Arousal

Bodily Feedback

These ingredients themselves are very insightful. A job well done. But the reader (well, me at least) is still left wondering: these are interesting processes and I can see that they are highly related to the 'feelings' aspect of emotion. But the question still remains: how do these bodily processes lead to mental feelings?

Upon which LeDoux postulates:

"When all of these systems function together a conscious emotional experience is inevitable."

And I know that many people feel this way. I myself think that it just doesn't make sense. He doesn't explain his statement any further, which is good because it would only weaken his claim.

As an after-afterword to this same chapter, he then feels the need to say something about the feelings of animals, in "Do Fish Have Feelings Too?". And this part is not written because his editor asked him to. This part was written because his own conscience told him to.

Wether animals have feelings or not was already answered implicitly by LeDoux in the same chapter. Since all animals have the 'three ingredients' named above, it would follow 'inevitably' that they have a conscious emotional experience - feelings.

But this is conclusion is not even mentioned by him. Instead he names the following arguments of why animals have a 'different' consciousness.

The human cortex is relatively larger - "This alone would give us reason to be cautious about attributing consciousness to other animals." -- Why? He does not say.

The prefrontal cortex (where working memory lives) is smaller

Most animals are not self-aware (unable to recognize themselves in the mirror) -- How is this related to emotion?

Natural language only exists in the human brain. It follows that the human brain is different from that of animals. It follows that we must be "cautious to attribute consciousness beyond our species"

He summarizes:

"Consciousness ... requires the capacity to relate several things at once (for example, the way a stimulus looks, memories of past experiences with that stimulus or related stimuli, a conception of the self as the experiencer). A brain that cannot form these relations, due to the absence of a cortical system that can put all of the information together at the same time, cannot be conscious."

These are not the words of a scientist or a philosopher. These are the words of a man that has sacrificed many hundreds of animals (mainly rats) to the greater good of the body of human knowledge. A man that has consciously invoked fear, again and again in the lives of his fellow creatures on this planet. Just for the sake of understanding. A man that denies the very feelings he has researched most of his life. A man that fears the truth.